OPERATING SYSTEMS

Operating system software is necessary for the user to be able to interact with both hardware and software. It must be installed first, before any application software can be installed.

N.B-‘Booting’ is how the operating system is loaded into main memory.

ROLES OF THE OPERATING SYSTEM

1.)MANAGING COMPUTER RESOURCES

The operating system software is what allows us to send a document to print i.e. it is the link between application programs and hardware.

1.      Command to print

2.      Instructions sent  from application software to OS

3.      OS selects printer

4.      Instruction form OS to start sending document

5.      Document sent to OS

6.      Document sent to printer

2.)   MANAGING FILES AND MEMORY

The operating system keeps track of where all files are stored in memory.This also allows you to copy, backup and restore files.

Users are able to store, search for, and access files using directories or folders

3.)  MAINTAINING SECURITY

The OS allows us to create profiles, user log-ins and passwords so that we can control who sees and modifies your files. It keeps a log of who uses the systems, what was viewed or accessed, and the times that it was used

How does the OS provide us with security?

There are several ways in which the OS allows us to have protection

• Passwords are used to protect files
• Anti-virus software allows us to scan files for viruses but it must be updated frequently
• Firewalls – software firewalls prevents hackers from being able to access confidential files especially when browsing the internet
• User profiles – different user profiles will allow us to sign in with different usernames and ID’s which allow us different user privileges eg. A student profile will have certain programs blocked when compared to a teacher profile
• Access logs – this is a record of each user that has signed in, the time each user stayed on and what was done on the computer. Administrators check the logs for abuse of resources.

4.)MANAGING TASKS

The operating system is able to do MULTI-TASKING which is “appear to be running” more than one program at the same time. The OS manages which instruction to send to the CPU (allocating processor time)

An example of this is printing a document whilst browsing the web or reading e-mail.

MULTI-USER operating systems allow more than one user to access data at the same time.

MULTI-PROCESSING refers to the ability of the computer to support more than one program at the same time, this is accomplished by linking 2 or more computers or processors which can then work on different programs simultaneously.

5.)   PROVIDING A USER INTERFACE.

The user interface is the user controllable part of the operating system.

There are 4 user interfaces

• MENU-DRIVEN(PULL-DOWN OR POP UP)
• GRAPHICAL USER INTERFACE - GUI(SUCH AS THE DESKTOP WITH ICONS)
• COMMAND-LINE or command-driven(WHERE COMMANDS ARE ENTERED TO DO TASKS)
• Touch screen interface –allows the user to touch the screen to make selections eg. ATM, tablets, restaurants( by cashiers), cell phones

DIRECTORIES OR FOLDERS

A directory is used to group files and documents that are related and place them in one location.

If you have a portfolio it would be based all on

one topic so the principle is the same

Files are stored with an extension which tells you the type of program it is associated with.

A path is the way in which we can locate a file.

Eg. C:/Desktop/Documents/Project.doc

Drive letter(c is hard drive)

Software

Programs or instructions that guide the computer to perform a specific task

Types of software include:

1.)Application Software

This is software that solves a particular problem or perform a particular task.

Types of application software include:

• General Purpose-Application not written for any specific business/organization but is adapted to the users needs.Examples include:Word processors,Spreadsheet software,Presentation software,Database management
• Integrated Software-This is group of related programs that comes in a package which allows data to be transferred easily between them.Examples include:Microsoft Office and AppleWorks
• Custom Written-This software is specially written to meet the specific needs of a company.For example,a system developed for a specific business or enterprise eg Sameer’s Flight School
• Specialized Software-Software was written for a specific purpose rather than a broad application area. Examples include:Accounting management,Reservation systems,HR management(payroll and attendance),Inventory control and Report/attendance in school

2.)Systems Software

This software governs the operation of both the hardware(controlling resources such as processors,memories and devices) and the software

Examples include:

Operating System Software-EG windows Linux, MacOS and utilities such as disk defragmentation, backup, file organizer, antivirus.